The large collection of cobblestone structures is just one of the many wonders of Western New York that calls to people all over the world.

From as far as Australia and Europe, outsiders are drawn to the mystery of the short-lived cobblestone era and what's left of it -- a stretch of roughly 700 stone structures from the Niagara Frontier past Rochester.

These few hundred structures were built in a mere three decades during the 19th century, mostly along the Niagara Escarpment and Route 104. And they're some of the only cobblestone structures in the world.

"These are pretty much quintessential Western New York," Matthew Ballard of the Cobblestone Society and Museum said. "Something that you can find outside of the area, but you're not going to easily find it. The highest concentration is right here in our own backyard."

A concentration of cobblestones credited to geology, when glaciers retreating from the last ice age dumped the deposit in large supply.

"You won't find that sort of deposit of those types of stones anywhere else in the country," Ballard said.

But we didn't start using it for construction until 1825. That's when another big project popped up along the same path where the buildings would rise.

"One of the overarching theories in regards to how this started was that there was the abundance of masons left over from building locks on the Erie Canal," Balalrd said.

Still, there are other theories, like the connection to the style of construction in England during one of the largest influxes of immigrants from the mother country in U.S. history.

And just like the mystery of why cobblestone construction started, the end of the era is theorized as well. Some say the availability of wood saw mills in the area made construction faster and more affordable than the cobblestone homes at the time.

"Why waste years when you could put up a wood framed house in a matter of weeks or months?" Ballard said.

Others point to one historical event for cobblestone's sudden end.

"Some have suggested that perhaps the Civil War sent a lot of the young men who would have been learning the trade of the mason off to war and many would not have returned home," Ballard said.

But no one can say for sure, which is why the cobblestone era remains one of the truly unknown stories of Western New York.